Systems and methods for ramping down magnetic resonance magnet

ABSTRACT

A magnetic resonance system may include a magnetic resonance magnet and a storage container configured to accommodate the magnetic resonance magnet. The storage container may also contain an endothermic liquid. The magnetic resonance system may further include a ramping-down device configured to trigger releasing electric energy by the magnetic resonance magnet. The first ramping-down device may include an electric energy consumption device configured to consume at least a portion of the released electric energy by the magnetic resonance magnet.

CROSS REFERENCE

This application claims priority of Chinese Patent Application No.201710535226.5 filed on Jul. 3, 2017, the entire contents of which arehereby incorporated by reference.

TECHNICAL FIELD

The present disclosure generally relates to systems and methods formagnetic resonance, and more specifically relates to methods and systemsfor ramping down in magnetic resonance system.

BACKGROUND

The magnetic resonance imaging (MRI) system in clinical is categorizedaccording to the type of the magnet (e.g., permanent magnet,superconducting magnet). The superconducting magnet has high magneticfield intensity (usually 1.5 or 3 Tesla). The superconducting magnet mayattract ferromagnetic materials nearby, and the attracted ferromagneticmaterial can be taken down only after the superconducting magnet isramped down (e.g., by ramping down the superconducting magnet).According to some regulations and laws, a ramping-down switch (orramping-down circuit) is required to ramp down the superconductingmagnet in an emergency. When metal tools, a patient with a metal implantor heart pacemaker close to the MRI system, the superconducting magnetmay be ramped down in a short time (usually 20 seconds) by turning onthe ramping-down switch.

When turning on the ramping-down switch, a heater may heat asuperconducting coil, then the superconducting coil may be ramped downand reverts to a resistive state, and the electric current flowingthrough the resistive part of the superconducting coil may be consumedin about 20 seconds and converted into a large amount of Joule heat. Thesuperconducting coil may usually be soaked in liquid helium in acryogenic container. The Joule heat would lead to the bulk of liquidhelium volatilized. After superconducting magnet is ramped down, theliquid helium need to be added to convert the superconducting magnetinto superconducting state, and adding the liquid helium would bringhuge cost.

SUMMARY

According to an aspect of the present disclosure, a magnetic resonancesystem may include a magnetic resonance magnet; a storage containerconfigured to contain the magnetic resonance magnet and an endothermicliquid; and a first ramping-down device configured to trigger releasingelectric energy from the magnetic resonance magnet, the firstramping-down device including an electric energy consumption deviceconfigured to consume at least a portion of the released electric energyby the magnetic resonance magnet.

In some embodiments, the first ramping-down device may include asuperconductor electrically coupled to the magnetic resonance magnet,the electric energy consumption device being electrically connected tothe superconductor; and a first heater configured to heat thesuperconductor, wherein when the first heater increases a temperature ofthe superconductor, the superconductor is disconnected, or thesuperconductor loses a superconduct condition, and the magneticresonance magnet releases the electric energy, and the electric energyconsumption device is configured to consume the electric energy releasedby the magnetic resonance magnet.

In some embodiments, the magnetic resonance magnet may include asuperconducting coil.

In some embodiments, the magnetic resonance magnet may include a secondramping-down device configured to increase a temperature of the magneticresonance magnet.

In some embodiments, the second ramping-down device may include a secondheater in the storage container, the second heater being configured toincrease the temperature of the magnetic resonance magnet.

In some embodiments, the first heater and the superconductor may bewithin the storage container.

In some embodiments, the superconductor may include a superconductingswitch.

In some embodiments, the first ramping-down device may include asuperconducting switch, wherein the superconducting switch is amechanical switch and connected to the magnetic resonance magnet, theelectric energy consumption device is connected to the superconductingswitch, and the electric energy consumption device is configured toconsume the electric energy released by the magnetic resonance magnetwhen the superconducting switch is turned off.

In some embodiments, a resistance value of the electric energyconsumption device may be less than a resistance value of the magneticresonance magnet in a non-superconducting state.

In some embodiments, a resistance value of the electric energyconsumption device may be less than a resistance value of thesuperconductor in a non-superconducting state.

According to another aspect of the present disclosure, a method forramping down a magnetic resonance magnet contained in a storagecontainer, the storage container containing an endothermic liquid, themethod may include ramping down the magnetic resonance magnet in a firstmode, the first mode may include: heating, by a first heater, asuperconductor electrically coupled to the magnetic resonance magnet,wherein when the first heater increases a temperature of thesuperconductor by heating the superconductor, the superconductor isdisconnected to the magnetic resonance magnet or resistance of thesuperconductor increases; releasing, from the magnetic resonance magnet,electric energy when the superconductor is disconnected to the magneticresonance magnet or the superconductor loses a superconduct condition;and consuming, by an electric energy consumption device residing outsidethe storage container, the electric energy released from the magneticresonance magnet, thereby ramping down the magnetic resonance magnet. Insome embodiments, the method may further include: obtaining anenvironmental condition related to the magnetic resonance magnet;determining whether the environmental condition related to the magneticresonance magnet satisfies a first condition; and ramping down themagnetic resonance magnet in the first mode in response to a result ofthe determination that the environmental condition related to themagnetic resonance magnet satisfies the first condition.

In some embodiments, the method may further include: determining whetherthe environmental condition related to the magnetic resonance magnetsatisfies a second condition; and ramping down the magnetic resonancemagnet in a second mode in response to a result of the determinationthat the environmental condition related to the magnetic resonancemagnet satisfies the second condition, the second mode being differentfrom the first mode.

In some embodiments, a ramping down speed of the second mode may befaster than that of the first mode.

In some embodiments, the second mode may include: heating, by a secondheater, a temperature of the magnetic resonance magnet, the secondheater being inside the storage container; releasing, by the magneticresonance magnet, energy when the magnetic resonance magnet is beingheated by the second heater, thereby ramping down the magnetic resonancemagnet; and absorbing, by the endothermic liquid contained in thestorage container, heat caused by the released energy from the magneticresonance magnet.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure is further described in terms of exemplaryembodiments. These exemplary embodiments are described in detail withreference to the drawings. These embodiments are non-limiting exemplaryembodiments, in which like reference numerals represent similarstructures throughout the several views of the drawings, and wherein:

FIG. 1 is a schematic diagram illustrating magnet ramping-down system inan MRI system according to some embodiments of the present disclosure.

DETAILED DESCRIPTION

In the following detailed description, numerous specific details are setforth by way of examples in order to provide a thorough understanding ofthe relevant disclosure. However, it should be apparent to those skilledin the art that the present disclosure may be practiced without suchdetails. In other instances, well-known methods, procedures, systems,components, and/or circuitry have been described at a relativelyhigh-level, without detail, in order to avoid unnecessarily obscuringaspects of the present disclosure. Various modifications to thedisclosed embodiments will be readily apparent to those skilled in theart, and the general principles defined herein may be applied to otherembodiments and applications without departing from the spirit and scopeof the present disclosure. Thus, the present disclosure is not limitedto the embodiments shown, but to be accorded the widest scope consistentwith the claims.

The terminology used herein is for the purpose of describing particularexample embodiments only and is not intended to be limiting. As usedherein, the singular forms “a,” “an,” and “the” may be intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the terms “comprise,”“comprises,” and/or “comprising,” “include,” “includes,” and/or“including,” when used in this specification, specify the presence ofstated features, integers, steps, operations, elements, and/orcomponents, but do not preclude the presence or addition of one or moreother features, integers, steps, operations, elements, components,and/or groups thereof.

It will be understood that the term “system,” “engine,” “unit,”“module,” and/or “block” used herein are one method to distinguishdifferent components, elements, parts, section or assembly of differentlevel in ascending order. However, the terms may be displaced by anotherexpression if they achieve the same purpose.

Generally, the word “module,” “unit,” or “block,” as used herein, refersto logic embodied in hardware or firmware, or to a collection ofsoftware instructions. A module, a unit, or a block described herein maybe implemented as software and/or hardware and may be stored in any typeof non-transitory computer-readable medium or another storage device. Insome embodiments, a software module/unit/block may be compiled andlinked into an executable program. It will be appreciated that softwaremodules can be callable from other modules/units/blocks or themselves,and/or may be invoked in response to detected events or interrupts.Software modules/units/blocks configured for execution on computingdevices may be provided on a computer-readable medium, such as a compactdisc, a digital video disc, a flash drive, a magnetic disc, or any othertangible medium, or as a digital download (and can be originally storedin a compressed or installable format that needs installation,decompression, or decryption prior to execution). Such software code maybe stored, partially or fully, on a storage device of the executingcomputing device, for execution by the computing device. Softwareinstructions may be embedded in firmware, such as an erasableprogrammable read-only memory (EPROM). It will be further appreciatedthat hardware modules/units/blocks may be included in connected logiccomponents, such as gates and flip-flops, and/or can be included ofprogrammable units, such as programmable gate arrays or processors. Themodules/units/blocks or computing device functionality described hereinmay be implemented as software modules/units/blocks but may berepresented in hardware or firmware. In general, themodules/units/blocks described herein refer to logicalmodules/units/blocks that may be combined with othermodules/units/blocks or divided into sub-modules/sub-units/sub-blocksdespite their physical organization or storage. The description mayapply to a system, an engine, or a portion thereof.

It will be understood that when a unit, engine, module or block isreferred to as being “on,” “connected to,” or “coupled to,” anotherunit, engine, module, or block, it may be directly on, connected orcoupled to, or communicate with the other unit, engine, module, orblock, or an intervening unit, engine, module, or block may be present,unless the context clearly indicates otherwise. As used herein, the term“and/or” includes any and all combinations of one or more of theassociated listed items.

In the present disclosure, the term “ramp down” “ramping-down” or“ramping down process” may refer to a process or an action decreasingthe magnetic field intensity of a magnetic resonance magnet from a firstlevel to a second level. In some embodiments, the first level (e.g.,1.5T, 3T, etc.) may be higher than the second level (e.g., 0.1 Gs, 10Gs, 100 Gs, 1000 Gs, etc.)

These and other features, and characteristics of the present disclosure,as well as the methods of operation and functions of the relatedelements of structure and the combination of parts and economies ofmanufacture, may become more apparent upon consideration of thefollowing description with reference to the accompanying drawings, allof which form a part of this disclosure. It is to be expresslyunderstood, however, that the drawings are for illustration anddescription only and are not intended to limit the scope of the presentdisclosure. It is understood that the drawings are not to scale.

FIG. 1 illustrates a magnetic resonance system according to someembodiments of the present disclosure. The magnetic resonance system mayinclude a magnetic resonance magnet 1, a storage container 34, a firstramping-down device 2, a second ramping-down device 3 configured to rampdown the magnetic resonance magnet 1. When being activated, the secondramping-down device 3 may be configured to ramp down the magneticresonance magnet 1.

The magnetic resonance magnet 1 may include a superconducting coilgroup. The storage container 34 may be configured to contain themagnetic resonance magnet 1. The storage container 34 may also containendothermic liquid (e.g., cryogenic liquid, such as liquid helium orliquid nitrogen, etc.). The endothermic liquid at an extremely lowtemperature (e.g., about −269 degrees Celsius.) may be used to maintainthe magnetic resonance magnet 1 in a superconducting state. Theresistance value of the magnetic resonance magnet 1 in thesuperconducting state may be or close to zero. An electric current mayflow through the magnetic resonance magnet 1 (e.g., the superconductingcoil group), generating a magnetic field. Since resistance value of themagnetic resonance magnet 1 in the superconducting state may be or closeto zero, the electric current may continuously flow in thesuperconducting coil group without any consumption In such case, theelectric energy of the electric current may remain in the magneticresonance magnet 1, and the magnetic field may be generated while themagnetic resonance magnet 1 remains in the superconducting state. Insome embodiments, increasing the temperature of the magnetic resonancemagnet 1 may render the magnetic resonance magnet 1 to change from thesuperconducting state to a resistive state. The resistance value of themagnetic resonance magnet 1 in the resistive state may be much greaterthan zero, and the magnetic resonance magnet 1 may become a resistor.The electric energy may be consumed by the resistor of magneticresonance magnet 1, producing Joule heat. In some embodiments, theendothermic liquid, which surrounds the magnetic resonance magnet 1, mayabsorb the Joule heat produced by the magnetic resonance magnet 1.

The first ramping-down device 2, when being activated, may be configuredto ramping down the magnetic resonance magnet 1. In some embodiments,the first ramping-down device 2 may be configured to ramp down themagnetic resonance magnet 1 by consuming the electric energy of magneticresonance magnet 1 by an electrical device that resides outside thestorage container (e.g., by an external electric energy consumptiondevice 24). The first ramping-down device 2 may include a superconductor22, an external electric energy consumption device 24, and a firstheater 25. The superconductor 22 may be coupled to the magneticresonance magnet 1 mechanically or electrically. Heating thesuperconductor 22 may change the initial superconducting state of thesuperconductor 22 into the resistive state. For example, thesuperconductor may lose the initial superconducting state when thetemperature of the superconductor rises for 1-2 Kelvin. The first heater25 may be configured to heat the superconductor such that thesuperconductor changes from its superconducting state to a resistivestate.

The external electric energy consumption device 24 may be connected withthe superconductor 22 and reside outside of the storage container 34.The first heater 25 may be configured to heat the superconductor 22.When the first heater 25 heats the superconductor 22, the resistancevalue of the superconductor 22 may increase, or the superconductor 22may be disconnected. As such the magnetic resonance magnet 1 and theexternal electric energy consumption device 24 may form a circuit.Accordingly, when the first heater 25 heats the superconductor 22, theexternal electric energy consumption device 24 may consume the electricenergy of the magnetic resonance magnet 1. In some embodiments, theresistance value of the external electric energy consumption device 24may be less than the resistance value of the magnetic resonance magnet 1in a non-superconducting state (e.g., the resistive state). In someembodiments, the resistance value of the external electric energyconsumption device 24 may be less than the resistance value of thesuperconducting coil group (e.g., the magnetic resonance magnet 1) inthe non-superconducting state (e.g., the resistive state). For example,the resistance value of the external electric energy consumption device24 may be 10Ω and the resistance value of the superconducting coil groupin the resistive state may be 100Ω. In some embodiments, the resistancevalue of the external electric energy consumption device 24 may be lessthan the resistance value of the superconductor 22 in thenon-superconducting state (e.g., the resistive state).

In some embodiments, the superconductor 22 and the superconducting coilgroup (e.g., the magnetic resonance magnet 1) may form a circuit whenthe superconductor 22 is connected to the superconducting coil group(e.g., the magnetic resonance magnet 1). The superconductor 22 may losesuperconductivity and be converted into a resistor having a largeresistance value when the first heater 25 heats the superconductor 22.Then the superconductor 22 and the external electric energy consumptiondevice 24 may form a parallel circuit using the superconducting coilgroup as a power source. Since the superconductor 22 has a largeresistance value when converted into a resistor, the electric energy inthe superconducting coil group may be consumed when flowing through theexternal electric energy consumption device 24. In some embodiments, thesuperconductor 22 may be a superconducting switch. The superconductingswitch may store less electric energy, while the superconducting coilgroup may store much more electric energy. Thus, the superconductingswitch would not generate much heat when the superconductor 22 isconverted into a resistor. Most of the electric energy in the circuitformed by the superconductor switch and the superconducting coil groupwhen the superconductor switch is turned on (e.g., the superconductorswitch is heated and converted into a resistor) may be consumed by theexternal electric energy consumption device 24, instead of thesuperconductor switch. In some embodiments, the superconductor 22 may beany type of superconducting devices storing less electric energy.

In some embodiments, the first ramping-down device 2 may include a firstramping-down switch group 26 and a first power source 27. The firstramping-down switch group 26, the first power source 27, and the firstheater 25 may be connected in series forming a circuit. When the firstramping-down switch group 26 is closed, the first power source 27 maysupply power to the first heater 25; then the first heater 25 maygenerate heat and heat the superconductor 22. The first ramping-downswitch group 26 may include one switch or at least two switchesconnected in parallel. The at least two switches may be installed atdifferent positions in an MRI scanning room and/or an MRI operatingroom, and people regardless of his or her position may operate the firstramping-down switch group 26 to control the first ramping-down device 2(by, example, closing one of the two switches).

In some embodiments, the external electric energy consumption device 24may include a plurality of power diodes connected in series or parallel.Preferably, a heat sink (not shown in FIG. 1), which may be configuredto dissipate heat generated by the external electric energy consumptiondevice 24, may be placed on the external electric energy consumptiondevice 24. More preferably, the external electric energy consumptiondevice 24 may be placed in a medium having a high specific heatcapacity, such as paraffin. The paraffin may solidify at roomtemperature and may absorb much heat when melting, thus ensuring theexternal electric energy consumption device 24 maintaining at a lowtemperature. In some embodiments, the external electric energyconsumption device 24, the superconductor 22, and the magnetic resonancemagnet 1 may be connected by a superconducting wire 4 to avoid energyconsumption by common wire, which may be damaged after being heated.

In some embodiments, the external electric energy consumption device 24may have a function of clamping pressure. The voltages of both ends ofthe external electric energy consumption device 24 may be not higherthan a threshold voltage (e.g., 10V) when the electric current flowsthrough external electric energy consumption device 24. In this way, thesuperconductor 22 may not be burnt out, and the consumption speed of theelectric current of the magnetic resonance magnet 1 may get controlled.

In some embodiments, the second ramping-down device 3 may include asecond heater 32 contained in the storage container 34. The secondheater 32 may be configured to heat the magnetic resonance magnet 1. Thesuperconducting coil group (i.e., the magnetic resonance magnet 1) maylose superconductivity (e.g., converted into the resistive state) and beconverted into a resistor having a large resistance value when thesecond heater 32 heats the magnetic resonance magnet 1. The electriccurrent stored in the superconducting coil group may be consumed in ashort time. A great amount of heat may be generated while the electriccurrent becomes or is close to zero, and a large amount of theendothermic liquid (e.g., liquid helium, liquid nitrogen, etc.)surrounding the superconducting coil group may be volatilized due to theabsorption of the heat.

The first ramping-down device 2 may consume the electric energy storedin the superconducting coil group via the external electric energyconsumption device 24. Since the resistance value of the externalelectric energy consumption device 24 may be much less than that of thesuperconducting coil group when the superconducting coil group loses itssuperconductivity, the speed of the external electric energy consumptiondevice 24 to consume electric energy may be less than the speed of thesuperconducting coil group to consume electric energy when thesuperconducting coil group loses its superconductivity (e.g., beingconverted into a resistive state). In addition, the time for theexternal electric energy consumption device 24 to completely consume theelectric energy of the superconducting coil group such that the electricenergy of the superconducting coil group becomes zero may be longer thanthe time for the superconducting coil group consumes its electric energyinto zero directly (e.g., by releasing a great amount of heat).Therefore, the ramping down speed of the first ramping-down device 2 maybe slower than that of the second ramping-down device 3. When themagnetic resonance magnet 1 is ramped down by the first ramping-downdevice 2, the superconducting coil group may not generate heat, therebyreducing the consumption of the liquid helium. In some embodiments, thesecond ramping-down device 3 may include a plurality of the secondheater 32, and each of the second heater 32 may heat differentsuperconducting coil groups. Alternatively, the second ramping-downdevice 3 may include one-second heater 32, and the one-second heater 32may heat different superconducting coil groups simultaneously.

Preferably, both the first heater 25 and the superconductor 22 may becontained in the storage container 34, thus the heat generated by thefirst heater 25 and the superconductor 22 may be absorbed by theendothermic liquid (e.g., liquid helium, liquid nitrogen, etc.) storedin the storage container 34 and may not conduct to an MRI device.

In some embodiments, the second ramping-down device 3 may furtherinclude a second ramping-down switch group 35 and a second power source36. The second ramping-down switch group 35, the second power source 36,and the second heater 32 may be connected in series to form a circuit.When the second ramping-down switch group 35 is closed, the second powersource 36 may supply power to the second heater 32. The second heater 32may generate heat and heat the superconductor 22. The secondramping-down switch group 35 may include one switch or at least twoswitches connected in parallel. The at least two switches may beinstalled at different positions in the MRI scanning room and/or the MRIoperation room, and people regardless of his or her position may operatethe second ramping-down switch group 35 to control the secondramping-down device 3 (by, example, closing one of the two switches). Insome embodiments, the first ramping-down device 2 and the secondramping-down device 3 may ramp down the magnetic resonance magnet 1simultaneously.

In some embodiments, the first ramping-down device may implement amechanical superconducting switch instead of the heating superconductorto cause the electric energy of the magnetic resonance magnet flowing tothe external electric energy consumption device 24. The mechanicalswitch may be connected to the magnetic resonance magnet, and theexternal electric energy consumption device may be connected to thesuperconducting switch. When ramping-down is required, disconnecting thesuperconducting switch from the circuit of the superconducting switchmay cause the magnetic resonance magnet 1 and the external electricenergy consumption device 24 to form a circuit. As such, the externalelectric energy consumption device 24 may consume the electric energy ofthe magnetic resonance magnet, and ramping down effect similar to theway of heating the superconductor may be achieved.

The present disclosure also provides a method of ramping down themagnetic resonance magnet using a first ramping-down mode, or a secondramping-down mode, or both modes. In a first ramping-down mode, theelectric energy of the magnetic resonance magnet 1 may be released andconsumed by the electric energy consumption device 24. In a secondramping-down mode, electric energy of the magnetic resonance magnet 1may be converted to heat and consumed by the endothermic liquidsurrounding the magnetic resonance magnet 1. The ramping-down speed ofthe first ramping-down mode implemented by the first ramping-down device2 may be slower than the ramping-down speed of the second ramping-downmode implemented by the second ramping-down device 3. The cost (e.g.,liquid volatilization) of the first ramping-down mode implemented by thefirst ramping-down device 2 may be lower than the cost of the secondramping-down mode implemented by the second ramping-down device 3. Insome embodiments, one of the first ramping-down mode or the secondramping-down mode may be selected to ramp down the magnetic resonancemagnet 1 according to the need. In some embodiments, the firstramping-down device 2 may be operated to implement the firstramping-down mode by a hospital technician instead of a service engineeror a field engineer. In some embodiments, the first and secondramping-down modes may be used simultaneously to ramp down the magneticresonance magnet 1.

In some embodiments, the first ramping-down mode may use the firstramping-down device 2 to ramp down the magnetic resonance magnet 1. Thefirst ramping-down device 2 may trigger releasing the electric energy bythe magnetic resonance magnet 1 in a storage container 34. The first ramping-down mode may include heating, by a first heater 25, asuperconductor electrically coupled to the magnetic resonance magnet 1.When the first heater 25 increases a temperature of the superconductorby heating the superconductor, the superconductor is disconnected to themagnetic resonance magnet or resistance value of the superconductorincreases. The first ram ping-down mode may also include releasing, bythe magnetic resonance magnet 1, electric energy when the superconductoris disconnected to the magnetic resonance magnet 1 or resistance valueof the superconductor increases. The first ramping-down mode may furtherinclude consuming the electric energy released by the magnetic resonancemagnet 1 by the electric energy consumption device 24, thereby rampingdown the magnetic resonance magnet 1. In some embodiments, the electricenergy consumption device 24 may reside outside the storage container34. In the first ramping-down mode, the superconductor 22 coupled to themagnetic resonance magnet 1 may be heated by a first heater 25. When thesuperconductor 22 is heated, it may lose its superconductivity and maybe disconnected to the magnetic resonance magnet 1 or the resistance ofthe superconductor 22 may increase and lose a superconduct condition.The magnetic resonance magnet 1 and the electric energy consumptiondevice 24 may form a circuit. Then the electric energy of the magneticresonance magnet 1 may release to the electric energy consumption device24. The electric energy consumption device 24 residing outside thestorage container 34 may consume the electric energy released by themagnetic resonance magnet 1, thereby the magnetic resonance magnet maybe ramped down. In some embodiments, the first heater 25 and thesuperconductor 22 may be inside the storage container 34. In someembodiments, the resistance value of the external electric energyconsumption device 24 may be less than the resistance value of themagnetic resonance magnet 1 in a non-superconducting state (e.g., theresistive state). In some embodiments, the resistance value of theexternal electric energy consumption device 24 may be less than theresistance value of the superconductor 22 in the non-superconductingstate (e.g., the resistive state).

In some embodiments, the second ramping-down mode may use the secondramping-down device 3 to ramp down the magnetic resonance magnet 1. Thesecond ramping-down mode may include heating, by a second heater 32, atemperature of the magnetic resonance magnet. The second heater 32 mayreside inside the storage container 34. The second ramping-down mode mayinclude releasing energy by the magnetic resonance magnet 1 when themagnetic resonance magnet 1 is heated by the second heater 32, therebyramping down the magnetic resonance. The second ramping-down mode mayfurther include absorbing the heat caused by the released energy fromthe magnetic resonance magnet by the endothermic liquid contained in thestorage container 34. In the second ramping-down mode, the second heater32 located in the storage container 34 may heat the magnetic resonancemagnet, then the magnetic resonance magnet 1 may convert from asuperconducting state into a resistive state. The magnetic resonancemagnet 1 in the resistive state may release its electric energy byconverting the electric energy into Joule heat, and the Joule heat maybe absorbed by the endothermic liquid contained in the storage container34.

In some embodiments, the method of ramping down the magnetic resonancemagnet 1 may also include selecting one of the first ramping-down modeand a second ramping-down mode. The first and second ramping-down modesmay have different ramping down speeds. In addition, the time to rampdown may be longer under the first ramping-down mode than that under thesecond ramping-down mode. In some embodiments, the method may includeselecting one of the two ramping-down modes according to anenvironmental condition. For example, if an environmental conditionrequires a shorter period of ramping down, the second ramping-down modemay be selected for ramping down the magnetic resonance magnet 1. Insome embodiments, a processor may receive a signal or data related tothe environmental conditions (e.g., signal from a sensor related to atemperature of the MRI scanning room of the a temperature of themagnetic resonance magnet). The processor may determine whether theenvironmental condition satisfies a first condition or a secondcondition. In response to a result of the determination that theenvironmental condition related to the magnetic resonance magnetsatisfies the first condition, the processor may generate a controlsignal to cause the first ramping-down device 2 to ramp down themagnetic resonance magnet in the first ramping-down mode. In response toa result of the determination that the environmental condition relatedto the magnetic resonance magnet satisfies the second condition, theprocessor may generate a control signal to cause the second ramping-downdevice 3 to ramp down the magnetic resonance magnet in the secondramping-down mode. In some embodiments, the first and secondramping-down modes may be used simultaneously to ramp down the magneticresonance magnet 1. For example, the processor may generate one or morecontrol signals to cause the first ramping-down device 2 and the secondramping-down device 3 to ramp down the magnetic resonance magnet at thesame time.

In some embodiments, the processor may execute computer instructions(e.g., program code) stored in a storage device (e.g., memory, a harddrive, a solid-state drive, a cloud-based storage) and perform functionsthereof in accordance with techniques described herein. The computerinstructions may include, for example, routines, programs, objects,components, data structures, procedures, modules, and functions, whichperform particular functions described herein. The processor may includeone or more hardware processors, such as a microcontroller, amicroprocessor, a reduced instruction set computer (RISC), anapplication specific integrated circuits (ASICs), anapplication-specific instruction-set processor (ASIP), a centralprocessing unit (CPU), a graphics processing unit (GPU), a physicsprocessing unit (PPU), a microcontroller unit, a digital signalprocessor (DSP), a field programmable gate array (FPGA), an advancedRISC machine (ARM), a programmable logic device (PLD), any circuit orprocessor capable of executing one or more functions, or the like, orany combinations thereof.

In some embodiments, the method of ramping down the magnetic resonancemagnet 1 may further include determining whether the environmentalcondition satisfies a first condition and ramping down the magneticresonance magnet 1 in the first ramping-down mode or the secondramping-down mode according to a result of the determination. Forexample, the first condition may be whether the magnetic resonancemagnet can be ramped down in a long period (e.g., above 20 seconds). Theenvironmental condition related to a magnetic resonance may be a ferrousobject or material (e.g., a coin, a wheelchair) attached to the magneticresonance magnet 1 and cannot be removed due to the magnetic fieldforce. The system may determine that the environmental conditionsatisfies the first condition since the magnetic resonance magnet 1 canbe ramped down in a long period. The system may also ramp down the themagnetic resonance magnet 1 using the first ramping-down mode. In someembodiments, the environmental condition may be obtained one or moresensors in the MRI scanning room (placed on the MRI system).Alternatively or additionally, an operator on-site may enter theenvironmental condition to the system, based on which the system mayrespond accordingly.

In some embodiments, the method of ramping down the magnetic resonancemagnet 1 may also include determining whether the environmentalcondition satisfies a second condition and ramping down the magneticresonance magnet 1 in the second ramping-down mode according to a resultof the determination that the environmental condition satisfies a secondcondition. For example, the second condition may be that the magneticresonance magnet 1 must be ramp down within a short period (e.g., 10seconds). Merely by way of example, the environmental condition may bethat a fire breaks out in the MRI scanning room. The system maydetermine whether this fire condition satisfies the second condition(i.e., the magnetic resonance magnet 1 must be ramp down d within ashort period). If so, the system may use the second ramping-down mode toramp down the the magnetic resonance magnet 1 since the magneticresonance magnet 1 may need to be quickly ramped down so that ferrousfire extinguish tools may be able to enter and be used in the MRIscanning room. In some embodiments, the environmental condition may beobtained one or more sensors in the MRI scanning room (placed on the MRIsystem). Alternatively or additionally, an operator on-site may enterthe environmental condition to the system, based on which the system mayresponse accordingly.

Having thus described the basic concepts, it may be rather apparent tothose skilled in the art after reading this detailed disclosure that theforegoing detailed disclosure is intended to be presented by way ofexample only and is not limiting. Various alterations, improvements, andmodifications may occur and are intended to those skilled in the art,though not expressly stated herein. These alterations, improvements, andmodifications are intended to be suggested by this disclosure and arewithin the spirit and scope of the exemplary embodiments of thisdisclosure.

Moreover, certain terminology has been used to describe embodiments ofthe present disclosure. For example, the terms “one embodiment,” “anembodiment,” and/or “some embodiments” mean that a particular feature,structure or characteristic described in connection with the embodimentis included in at least one embodiment of the present disclosure.Therefore, it is emphasized and should be appreciated that two or morereferences to “an embodiment” or “one embodiment” or “an alternativeembodiment” in various portions of this specification are notnecessarily all referring to the same embodiment. Furthermore, theparticular features, structures or characteristics may be combined assuitable in one or more embodiments of the present disclosure.

Furthermore, the recited order of processing elements or sequences, orthe use of numbers, letters, or other designations, therefore, is notintended to limit the claimed processes and methods to any order exceptas may be specified in the claims. Although the above disclosurediscusses through various examples what is currently considered to be avariety of useful embodiments of the disclosure, it is to be understoodthat such detail is solely for that purpose and that the appended claimsare not limited to the disclosed embodiments, but, on the contrary, areintended to cover modifications and equivalent arrangements that arewithin the spirit and scope of the disclosed embodiments. For example,although the implementation of various components described above may beembodied in a hardware device, it may also be implemented as a softwareonly solution, for example, an installation on an existing server ormobile device.

Similarly, it should be appreciated that in the foregoing description ofembodiments of the present disclosure, various features are sometimesgrouped together in a single embodiment, FIGURE, or description thereofto streamline the disclosure aiding in the understanding of one or moreof the various inventive embodiments. This method of disclosure,however, is not to be interpreted as reflecting an intention that theclaimed subject matter requires more features than are expressly recitedin each claim. Rather, inventive embodiments lie in less than allfeatures of a single foregoing disclosed embodiment.

We claim:
 1. A magnetic resonance system, comprising: a magneticresonance magnet; a storage container configured to contain the magneticresonance magnet and an endothermic liquid; and a first ramping-downdevice configured to trigger releasing electric energy from the magneticresonance magnet, the first ramping-down device including an electricenergy consumption device configured to consume at least a portion ofthe released electric energy by the magnetic resonance magnet.
 2. Themagnetic resonance system of claim 1, wherein the first ramping-downdevice further includes: a superconductor electrically coupled to themagnetic resonance magnet, the electric energy consumption device beingelectrically connected to the superconductor; and a first heaterconfigured to heat the superconductor, wherein when the first heaterheats the superconductor, the superconductor is disconnected or loses asuperconduct condition, and the magnetic resonance magnet releases theelectric energy, and the electric energy consumption device consumes theelectric energy released by the magnetic resonance magnet.
 3. Themagnetic resonance system of claim 1, wherein the magnetic resonancemagnet includes a superconducting coil.
 4. The magnetic resonance systemof claim 1, further comprising a second ramping-down device configuredto increase a temperature of the magnetic resonance magnet.
 5. Themagnetic resonance system of claim 4, wherein the second ramping-downdevice further includes a second heater in the storage container, thesecond heater being configured to increase the temperature of themagnetic resonance magnet.
 6. The magnetic resonance system of claim 2,wherein the first heater and the superconductor are within the storagecontainer.
 7. The magnetic resonance system of claim 2, wherein thesuperconductor includes a superconducting switch.
 8. The magneticresonance system of claim 1, wherein the first ramping-down deviceincludes a superconducting switch, wherein the superconducting switch isa mechanical switch and connected to the magnetic resonance magnet, theelectric energy consumption device is connected to the superconductingswitch, and the electric energy consumption device is configured toconsume the electric energy released by the magnetic resonance magnetwhen the superconducting switch is turned off.
 9. The magnetic resonancesystem of claim 2, wherein a resistance value of the electric energyconsumption device may be less than a resistance value of the magneticresonance magnet in a non-superconducting state.
 10. The magneticresonance system of claim 2, wherein a resistance value of the electricenergy consumption device may be less than a resistance value of thesuperconductor in a non-superconducting state.
 11. A method for rampingdown a magnetic resonance magnet contained in a storage container, thestorage container containing an endothermic liquid, the methodcomprising: ramping down the magnetic resonance magnet in a first mode,the first mode including: heating, by a first heater, a superconductorelectrically coupled to the magnetic resonance magnet, wherein when thefirst heater increases a temperature of the superconductor by heatingthe superconductor, the superconductor is disconnected to the magneticresonance magnet or the superconductor loses a superconduct condition;consuming electric energy from the magnetic resonance magnet, by anelectric energy consumption device residing outside the storagecontainer, when the superconductor is disconnected to the magneticresonance magnet or the superconductor loses the superconduct condition,thereby ramping down the magnetic resonance magnet.
 12. The method ofclaim 11, further comprising: obtaining an environmental conditionrelated to the magnetic resonance magnet; determining whether theenvironmental condition related to the magnetic resonance magnetsatisfies a first condition; and ramping down the magnetic resonancemagnet in the first mode in response to a result of the determinationthat the environmental condition related to the magnetic resonancemagnet satisfies the first condition.
 13. The method of claim 12,further comprising: determining whether the environmental conditionrelated to the magnetic resonance magnet satisfies a second condition;and ramping down the magnetic resonance magnet in a second mode inresponse to a result of the determination that the environmentalcondition related to the magnetic resonance magnet satisfies the secondcondition, the second mode being different from the first mode.
 14. Themethod of claim 13, wherein a ramping down speed of the second mode isfaster than that of the first mode.
 15. The method of claim 13, whereinthe second mode includes: heating, by a second heater, a temperature ofthe magnetic resonance magnet, the second heater being inside thestorage container; releasing, by the magnetic resonance magnet, energywhen the magnetic resonance magnet is being heated by the second heater,thereby ramping down the magnetic resonance magnet; and absorbing, bythe endothermic liquid contained in the storage container, heat causedby the released energy from the magnetic resonance magnet.
 16. Themethod of claim 11, wherein the magnetic resonance magnet is asuperconducting coil.
 17. The method of claim 11, wherein the firstheater and the superconductor are inside the storage container.
 18. Themethod of claim 11, wherein the superconductor is a superconductingswitch.
 19. The method of claim 11, wherein a resistance value of theelectric energy consumption device is less than a resistance value ofthe magnetic resonance magnet in a non-superconducting state.
 20. Themethod of claim 11, wherein a resistance value of the electric energyconsumption device is less than a resistance value of the superconductorin a non-superconducting state.